Patent Application
20210363831
The present invention relates to a system and method for a drill bit.
Drill bits are used to drill holes for various purposes. Drill bits are used in the oil and gas industry to drill for oil and gas. These drill bits are supported by high powered pumps which can pump water and other drilling liquids at 1000 psi downhole. However, other drilling systems do not have access to the costly and expensive high-pressure pumps available in the oil and gas industry. One such example is drilling water wells. Consequently, there is a need for a drill bit which can be used in water wells.
The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will be best understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein:
Several embodiments of Applicant's invention will now be described with reference to the drawings. Unless otherwise noted, like elements will be identified by identical numbers throughout all figures. The invention illustratively disclosed herein suitably may be practiced in the absence of any element which is not specifically disclosed herein.
Water or other drilling liquid is pumped to the drill bit. The drilling liquid serves many purposes. It cools the drill bits, and it removes debris which has been cut. In many typical drill bits, there are a plurality of smaller outlets located on the downstream face of the bit. Upstream and downstream refer to relative locations on the bit. A downstream location is further downhole than an upstream location. In
In many typical drill bits there are a plurality of outlets on the downstream face of the drill bit. A drilling liquid is pumped downhole and exits through the downstream face through the outlets. With high pressure applications, the pressure is sufficient to exit the downstream face, pick up debris on the cutting face, and then exit upstream.
However, when lower pressure applications are utilized, there is insufficient pressure to force the drilling liquid through the plurality of holes. This makes the drill bit susceptible to fouling and plugging as the liquid pressure is insufficient to remove the debris and prevent fouling. In effect, as the drill bit cuts debris, the debris is shoved into the outlet holes. Because the drilling liquid is not sufficiently high pressure, plugging and fouling results. This reduces the effectiveness of the drill bit. The drill bit might need to either be retrieved from its downhole location and repaired or replaced, or it needs to be cleaned. This results in significant downtime. Fouling also reduces the cooling effect of the drilling liquid. The drilling liquid is also used to clean the bit and the hole, and low pressure and low volume liquid does not clean as effectively.
Consequently, many of the oil field drill bits are inapplicable to the lower pressures of other applications, such as water well drilling. To overcome this disadvantage, in one embodiment an open drill bit with PDC cutters is described. As used herein, an open drill bit with PDC cutters refers to a drill bit which has one central opening and which utilizes PDC cutters. An open bit is dissimilar from a bit which comprises a plurality of comparatively smaller openings. Having smaller openings reduces the volume flow through each separate opening. As such, an open bit has much higher volume through the central opening than non-open bits.
Turning to
In one embodiment the central opening refers to a single opening which is open at the upstream end of the drill bit and which extends to the downstream end of the drill bit. Thus, the central opening 101 extends throughout the entirety of the drill bit. Thus, as depicted in
A higher volume flow, along with a centrally focused flow, has several benefits. First, higher volume prevents plugging and fouling. The comparatively larger opening is not going to get plugged or foul as easily as the plurality of smaller opening.
Second, the higher volume is more suitable with comparatively lower pressure associated with water well drilling. Such pumps generally operate in the 200-300 psi range. A large open and central opening 101 ensures a steady flow through the bit 100.
The size of the central opening 101 can vary depending upon the application. In one embodiment the diameter of the central opening 100 at the downstream end is greater than 50% of the diameter of the outer wall 103 at the downstream end of the bit face. In other embodiment the diameter of the central opening 100 at the downstream end is greater than 80% of the diameter of the outer wall 103 at the downstream end of the bit face.
As noted, in one embodiment the open bit comprises only a single central opening 101. Thus, the entire volume of drilling liquid exits the same central opening 101.
As shown, the bit 100 comprises four separate blades 102. As depicted, these extend outward downstream of the central opening 101. As shown, each of the blades 102 comprise an L-shape and extend to partially over the central opening 101. The blades 102 can comprise various materials and shapes to assist in drilling.
While shown as having four separate blades 102, this is for illustrative purposes only and should not be deemed limiting. In other embodiments there is only a single blade 102, whereas in other embodiments there are two or more blades 102. At least a portion of the blades are located downstream of the downstream face. In one embodiment at least a portion of the blades intersect and partially cover the central opening. Thus, if a user were to insert an object through the central opening the object could contact one or more blades.
As depicted, the blades 102 comprise one or more cutters 107. In one embodiment the cutters comprise PDC material. In such embodiments the blades 102 are fitted with industrial diamond cutters which are used to cut and drill the hole. While one embodiment has been described using PDC cutters, this is for illustrative purposes only and should not be deemed limiting.
As can be seen in
As depicted, the drill bit 100 with PDC cutters comprises a coupler portion 105. The coupler portion 105 is upstream of the head portion 106. The coupler portion 105 is used to couple the drill bit 100 to an upstream drilling rig or line. The coupler portion 105 can comprise any mechanical device or system to couple a drill bit 100. As depicted, the coupler portion 105 comprises threading.
The head portion 106 is downstream of the coupler portion 105 when downhole. The head portion 106 and the coupler portion 105 can be integrally made from a single piece, or they can comprise separate pieces which are connected by welding, screwing, bolts, etc.
The blades 102 are coupled, as depicted, and in one embodiment, to the head portion 106. The blades 102 can be coupled with any method or device known in the art including welding, soldering, screws, bolts, etc. In other embodiments the blades 102 can be integrally made with the head portion 106.
The drill bit 100 on the left has a head 106 which has a substantially uniform cross section. Thus, the shape of the head 106 on the left is generally uniform as it extends from the coupler 105 to the downstream end of the bit. Conversely, the drill bit 100 on the right has a head with a non-uniform cross section. As can be seen, the head 106 on the right starts with a wider diameter where it is adjacent to the coupler 105. The head 106 flares outwardly where it is adjacent to the coupler 105. The cross-sectional diameter is larger upstream. The cross-sectional diameter decreases to a point and then the cross-sectional shape becomes more uniform. This illustrates that the bits 100 can have various shapes. Despite a varying shape, the bit 100 on the right still has a single central opening 101. This allows for the same benefits previously discussed herein.
The drill bits 100 discussed herein can comprise the same materials as previous bits. The bits and blades can comprise metal, plastics, and combinations thereof, and any material typically used in traditional drill bits. These include metals, plastics, diamond and synthetic components, etc.
As noted, in one embodiment the blades 102 further comprise PDC cutters 107. The PDC cutters have many benefits over other non-PDC cutters such as carbide cutting edges. Carbide cutting edges do not last as long as PDC bits.
In one embodiment, the blades 102 comprise mild steel or other similar materials. As noted, in one embodiment the blades 102 are welded or otherwise coupled to the head 106. In such embodiments the blades 102 are not integrally made with the head 106. This is an advantage in some embodiments as it allows for easier and more cost-effective manufacturing and repair. In some embodiments if the blades 102 were made from a different material, and/or if the blades 102 and head 106 are integrally made, the head 106 and blades 102 had to be placed inside a kiln in order to repair a damaged cutter and/or blade 102. However, in embodiments wherein the blades 102 comprise mild steel, the manufacturing and repair does not require a kiln. Instead, a cutter 107 and/or blade 102 can be repaired on-site or in a mechanic shop. This reduces downtime due to a repair. In some embodiments the shape of the flat steel blade 102 reduces the cost of repair and manufacture of the bit.
The size and shape of the drill bits with PDC cutters can also be varied. As shown in both figures, the diameter and shape of the bits can vary depending upon the application.
While the figures depict an embodiment with four blades 102, this is for illustrative purposes and should not be deemed limiting. There can be virtually any number of cutters which have virtually any shape, cross section, length, etc.
One embodiment discussed herein discloses a drill bit. Another embodiment a system for low pressure drilling is disclosed. In one embodiment low pressure drilling is drilling whereby the pump operates at less than 400 psi when drilling. In another embodiment low pressure drilling is drilling whereby the pump operates at less than 300 psi when drilling. Low pressure drilling includes water well drilling and is different than high pressure oil well drilling, as an example. The system uses a bit as discussed herein. The system also utilizes a low pressure pump. As noted, the pump produces a drilling pressure less than about 400 psi in some embodiments, and less than about 300 psi in other embodiments.
As noted, the open drill bit with PDC cutters described herein has many different benefits. First, it allows relatively lower pumps, in the 200-300 psi range to be used to effectively drill holes. As noted, these pumps are more traditionally used with water well drilling.
Third, the effectiveness of the drill bit with PDC cutters is improved compared to prior art bits. Because a steady volume and pressure of water is utilized, the susceptibility to fouling is decreased substantially. When the drill bit fouls, the effectiveness of the drilling is reduced. This is because the drill face is not properly cleaned, the debris is not properly removed, and the drill bit is not properly cooled. The central opening reduces these problems and provides for these additional benefits.
While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.
This application claims priority to U.S. provisional patent application No. 63/021,461 filed May 7, 2020, the entirety of both are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63021461 | May 2020 | US |
